A dehydroabietylamine sulfonamide derivative, a preparation method thereof, and a drilling fluid

Abstract

The present application relates to a kind of dehydroabietylamine sulfamide derivatives and its preparation method, drilling fluid, the dehydroabietylamine sulfamide derivative can solve barite high-temperature settlement and system stability problem in drilling fluid system when being used as drilling fluid additive, the existence of the ternary phenanthrene skeleton structure and sulfamide group of dehydroabietyl sulfamide compound makes it can continuously maintain good emulsification and dispersion performance at higher temperature, ensures its efficient application in deep oil and gas exploration work.

Description

Technical Field

[0001] This invention relates to the field of oilfield development technology, specifically to a dehydroafamidol sulfonamide derivative and its preparation method, as well as drilling fluid. Background Technology

[0002] Currently, as the drilling and mining process progresses, the drilling depth is getting deeper and deeper, and the drilling environment is becoming more and more severe. The drilling process usually faces high temperature and high pressure environments, and the performance requirements of the drilling fluid used in drilling are becoming increasingly stringent.

[0003] For example, CN108239528A describes an oil-based drilling fluid whose technical solution is as follows: the base fluid is biodiesel, and the remaining additives, by weight percentage, are: 10%-25% calcium chloride solution, 1%-3% emulsifier, 2%-3% wetting agent, 3%-5% organic clay, 2%-3% calcium oxide, 2%-4% plugging agent, and 0.2%-1% shearing agent. The fine particles contained in this solution deform at high temperatures, forming nano- and micron-sized particles with good temperature resistance. These particles are then modified to improve the plugging effect while maintaining the strong inhibitory properties of the oil-based drilling fluid, ensuring wellbore stability in easily collapsible formations; simultaneously, it reduces environmental pollution.

[0004] However, the drilling fluid currently used still has poor high-temperature stability, which leads to the sedimentation of the weighting agent. Summary of the Invention

[0005] In view of the problems existing in the prior art, the purpose of the present invention is to provide a dehydroafamidine sulfonamide derivative and its preparation method, as well as a drilling fluid, to solve the defect that the drilling fluid still has poor high-temperature stability at high temperatures, which leads to the sedimentation of the weighting agent.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a dehydroaflavinol sulfonamide derivative, wherein the structural formula of the dehydroaflavinol sulfonamide derivative is as follows:

[0008]

[0009] In the formula, R includes straight-chain or branched alkyl groups with 2-20 carbon atoms.

[0010] The dehydroabiamine sulfonamide derivative provided by this invention uses the rigid tricyclic phenanthrene structure of dehydroabiamine as the basic framework and introduces sulfonamide groups, which enable it to maintain good emulsification and dispersion properties at high temperatures when used as a drilling fluid additive, thus ensuring its efficient application in deep oil and gas exploration.

[0011] As a preferred embodiment of the present invention, R comprises a straight-chain or branched alkyl group having 2-10 carbon atoms;

[0012] Preferably, R includes one of ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, or n-hexyl.

[0013] As a preferred embodiment of the present invention, the dehydroaflavinol sulfonamide derivative is selected from any one of the following compounds:

[0014]

[0015]

[0016] In a second aspect, the present invention provides a method for preparing the dehydroaflavinol sulfonamide derivative as described in the first aspect, the method comprising:

[0017] The dehydroafylamine solution was added dropwise to an alkylsulfonyl chloride solution to carry out the reaction, and the reaction solution was obtained.

[0018] The reaction solution was extracted, and the resulting organic phase was dried, filtered, and rotary evaporated to obtain a dehydroafiminosulfonamide derivative.

[0019] As a preferred embodiment of the present invention, the molar ratio of dehydroabimethamine to alkylsulfonyl chloride in the reaction is 1:(0.5-2).

[0020] Preferably, the reaction time is 2-6 hours.

[0021] Preferably, the reaction temperature is 25-80°C.

[0022] As a preferred embodiment of the present invention, the molar ratio of dehydroabimethamine and alkylsulfonyl chloride in the reaction is 1:(1-1.2).

[0023] Preferably, the reaction time is 3-4 hours.

[0024] Preferably, the reaction temperature is 30-60°C.

[0025] As a preferred embodiment of the present invention, an organic weak base is also added dropwise during the reaction process.

[0026] Preferably, the organic weak base includes pyridine and / or triethylamine.

[0027] Thirdly, the present invention provides a drilling fluid comprising the dehydroafamidosulfonamide derivative as described in the first aspect.

[0028] As a preferred embodiment of the present invention, the drilling fluid includes an oil-based drilling fluid.

[0029] As a preferred embodiment of the present invention, the drilling fluid comprises: an oil phase, an emulsifier, an organic clay, calcium, a filtration loss reducer, a weighting agent, and the dehydroafamidine sulfonamide derivative.

[0030] Compared with existing technical solutions, the present invention has the following beneficial effects:

[0031] (1) The dehydroabisulfonamide derivative provided by this invention, as a drilling fluid additive, solves the problems of high-temperature sedimentation of barite and system stability in the drilling fluid system. The ternary phenanthrene skeleton structure and the presence of sulfonamide groups of the dehydroabisulfonamide compound enable it to maintain good emulsification and dispersion performance at higher temperatures. Its high temperature resistance can reach 180℃, ensuring its efficient application in deep oil and gas exploration. Attached Figure Description

[0032] Figure 1 These are the infrared spectra of dehydroabimethamine and product DBS1 in the embodiments of the present invention;

[0033] Figure 2 This is product DBS1 in the embodiments of the present invention. 13 C NMR spectrum;

[0034] Figure 3 This is product DBS1 in the embodiments of the present invention. 1 H NMR spectrum.

[0035] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims. Detailed Implementation

[0036] To better illustrate the present invention and facilitate understanding of its technical solutions, typical but non-limiting embodiments of the present invention are as follows:

[0037] This embodiment provides a dehydroaflavinol sulfonamide derivative, the structural formula of which is:

[0038]

[0039] In the formula, R includes straight-chain or branched alkyl groups with 2-20 carbon atoms.

[0040] For example, R can be selected as ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, dodecyl, heptadecanyl, etc.

[0041] For example, the dehydroaflavinol sulfonamide derivative may be any one of the following compounds:

[0042]

[0043] Furthermore, the present invention provides a method for preparing the aforementioned dehydroafylamine sulfonamide derivative, comprising: adding a dehydroafylamine solution dropwise into an alkyl sulfonyl chloride solution to carry out a reaction, thereby obtaining a reaction solution;

[0044] The reaction solution was extracted, and the resulting organic phase was dried, filtered, and rotary evaporated to obtain a dehydroafiminosulfonamide derivative.

[0045] The solvents used in the dehydroabimethamine solution and the alkylsulfonyl chloride solution can be commonly used synthetic solvents in the field, such as dichloromethane.

[0046] During the preparation process, the alkyl sulfonyl chloride in the alkyl sulfonyl chloride solution can be selected adaptively based on the R group in the product. For example, if R is ethyl, then ethyl sulfonyl chloride (CAS No.: 594-44-5) is selected; if R is n-propyl, then propyl sulfonyl chloride (CAS No.: 10147-36-1) is selected; if R is n-butyl, then butyl sulfonyl chloride (CAS No.: 2386-60-9) is selected; and so on. Dichlorophosphate can also be selected from 2-pentyl sulfonyl chloride (CAS No.: 59427-30-4), dodecyl sulfonyl chloride (CAS No.: 10147-40-7), and isobutane sulfonyl chloride (CAS No.: 35432-36-1).

[0047] The concentration of the dehydroabimethamine solution used should be below the saturation concentration. For example, it can be selected as 0.05-0.2 g / mL, such as 0.05 g / mL, 0.06 g / mL, 0.07 g / mL, 0.08 g / mL, 0.09 g / mL, 0.1 g / mL, 0.12 g / mL, 0.14 g / mL, 0.16 g / mL, 0.18 g / mL or 0.2 g / mL, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0048] The concentration of the alkyl sulfonyl chloride solution used should be below the saturation concentration. For example, it can be selected as 1-4 mol / L, such as 1 mol / L, 1.2 mol / L, 1.4 mol / L, 1.6 mol / L, 1.8 mol / L, 2 mol / L, 2.2 mol / L, 2.4 mol / L, 2.6 mol / L, 2.8 mol / L, 3 mol / L, 3.2 mol / L, 3.4 mol / L, 3.6 mol / L, 3.8 mol / L, or 4 mol / L, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0049] The extractant used in the extraction process can be chloroform or a saturated salt solution such as saturated sodium chloride, which are commonly used extractants in the art. Drying can be carried out using common solid drying methods in the art, such as anhydrous sodium sulfate and / or anhydrous magnesium sulfate, or other common drying methods in the art. Rotary evaporation is used to remove residual reactant solvents from the product. Specific control parameters can be designed according to actual needs, but should not affect the performance of the product obtained by the present invention.

[0050] Specifically, the molar ratio of dehydroabimethamine to alkylsulfonyl chloride in the reaction is 1:(0.5-2), for example, it can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9 or 1:2, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0051] In this invention, if the molar ratio of dehydroabimethamine to alkylsulfonyl chloride is too large or too small during the reaction, the utilization rate of the reaction raw materials will be low, and subsequent purification operations will be required, increasing costs. Therefore, the preferred molar ratio of dehydroabimethamine to alkylsulfonyl chloride is 1:(1-1.2).

[0052] Specifically, the reaction time is 2-6 hours, for example, it can be 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3 hours, 3.2 hours, 3.4 hours, 3.6 hours, 3.8 hours, 4 hours, 4.2 hours, 4.4 hours, 4.6 hours, 4.8 hours, 5 hours, 5.2 hours, 5.4 hours, 5.6 hours, 5.8 hours, or 6 hours, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0053] Specifically, the reaction temperature is 25-80℃, for example, it can be 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃ or 80℃, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0054] During the dropwise addition process, an ice bath is used to maintain the material temperature at 0-5℃. After the dropwise addition is completed, the reaction is carried out at a reaction temperature of 25-80℃ for 3-4 hours.

[0055] Specifically, a weak organic base is also added dropwise during the reaction process.

[0056] Specifically, the organic weak base includes pyridine and / or triethylamine.

[0057] The amount of organic weak base added is such that the molar ratio of organic weak base to dehydroabimethamine is 1:(1-2.2), for example, it can be 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2 or 1:2.2, etc., but is not limited to the listed values; other unlisted values ​​within this range are also applicable. Simultaneously, the dropping rate of the organic weak base is the same as the dropping rate of the dehydroabimethamine solution, and the dropping rate can be selected from 1-3 mL / min, for example, it can be 1 mL / min, 1.2 mL / min, 1.4 mL / min, 1.6 mL / min, 1.8 mL / min, 2 mL / min, 2.2 mL / min, 2.4 mL / min, 2.6 mL / min, 2.8 mL / min or 3 mL / min, etc., but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0058] Furthermore, the present invention provides a drilling fluid comprising the aforementioned dehydroafamidosulfonamide derivative.

[0059] Specifically, the drilling fluid includes oil-based drilling fluid.

[0060] Specifically, the drilling fluid includes: an oil phase, an emulsifier, an organic clay, calcium, a filtration loss reducer, a weighting agent, and the dehydroafamidine sulfonamide derivative.

[0061] Further, by weight, the drilling fluid comprises 200-300 parts of oil phase, 20-30 parts of emulsifier, 6-8 parts of organic clay, 40-80 parts of calcium, 8-15 parts of filtration loss reducer, 600-750 parts of weighting agent, and 5-120 parts of dehydroabiaminophosphonamide derivative.

[0062] The oil phase used can be selected as white oil or synthetic oil of long-chain alkane with 9-20 carbon atoms.

[0063] The emulsifier used can be selected from commonly used emulsifiers in this field, such as HT-MUL emulsifier.

[0064] The organic soil used can be selected from bentonite, modified bentonite, attapulgite, montmorillonite and other commonly used organic soils in the field, and a combination of one or at least two kinds can be selected.

[0065] The calcium includes calcium salts and calcium oxides.

[0066] The calcium salts are soluble calcium salts, such as calcium chloride and calcium nitrate; calcium oxides include calcium oxide.

[0067] The filtration loss reducing agent can be selected from commonly used filtration loss reducing agents in the art, such as humic acid amide, lignite resin, and emulsified asphalt, and can be selected from one or at least two kinds of combinations.

[0068] The weighting agent can be selected from commonly used weighting agents in the art, such as barite, iron ore powder, limestone powder, and manganese tetroxide, and can be selected from one or at least two kinds of combinations.

[0069] To more clearly illustrate the excellent performance of the dehydroafylamine sulfonamide derivative provided by the present invention, the following specific examples are provided:

[0070] Example 1

[0071] This embodiment provides a dehydroaflavinol sulfonamide derivative with the following structural formula:

[0072]

[0073] The preparation process is as follows:

[0074] 9.48 mL (0.1 mol) of ethylsulfonyl chloride was dissolved in 50 mL of dichloromethane. 30.049 g (0.1 mol) of dehydroabimethamine in dichloromethane and 13.941 mL (0.1 mol) of triethylamine in dichloromethane were added dropwise at a uniform rate over an ice bath for 1 hour. The reaction was stirred at 25 °C for 3 hours (the molar ratio of dehydroabimethamine to alkylsulfonyl chloride was 1:1) to obtain a solution. The solution was extracted with saturated brine, and after separation, excess anhydrous magnesium sulfate was added to the lower organic layer and dried overnight. The solution was then filtered, rotary evaporated, dried, and ground into powder to obtain the product, designated DPS1, with a yield of 67.40%.

[0075] Example 2

[0076] This embodiment provides a dehydroaflavinol sulfonamide derivative with the following structural formula:

[0077]

[0078] The preparation method is as follows:

[0079] 11.26 mL (0.1 mol) of propylsulfonyl chloride was dissolved in 50 mL of dichloromethane. 30.049 g (0.1 mol) of dehydroabimethamine in dichloromethane and 13.941 mL (0.1 mol) of triethylamine in dichloromethane were added dropwise at a uniform rate over an ice bath for 1 hour. The reaction was stirred at 60 °C for 3 hours (the molar ratio of dehydroabimethamine to alkylsulfonyl chloride was 1:1) to obtain a solution. The solution was extracted with saturated brine, and after separation, excess anhydrous magnesium sulfate was added to the lower organic layer and dried overnight. The solution was then filtered, rotary evaporated, dried, and ground into powder to obtain the product, designated DBS2, with a yield of 79.94%.

[0080] To verify that the product prepared in this invention is a dehydroafoamine sulfonamide derivative, infrared spectroscopy was performed on dehydroafoamine and the product DBS1 obtained in Example 1, and nuclear magnetic resonance (NMR) was also performed on DBS1. Figure 1-3 As shown.

[0081] Figure 1 In the image, a and b are the infrared spectra of dehydroabimethamine and DBS1, respectively; among them, 2931 cm⁻¹ -1 Its right subpeak is attributed to the characteristic CH absorption peaks of dehydroaflavin and methylene; 1601 cm⁻¹ -1 820cm -1 The vibrational absorption peak attributable to the terpene structure is consistent with the absorption characteristics of dehydroabietic amide compounds. 3278 cm⁻¹ -1 The peak is sharp and single, belonging to the stretching vibration of secondary amide NH; 1324 cm⁻¹ -1 1148cm -1 The characteristic peaks at this location are attributed to the asymmetric vibration and stretching vibration bands of O=S=O, consistent with the absorption characteristics of sulfonamide compounds. This preliminarily indicates that the sulfonamide compound DBS1 has been successfully synthesized.

[0082] Figure 2 The carbon NMR spectrum of DBS1 is shown; the proton peak positions for each carbon atom are labeled ( 13 CNMR (101MHz, CDCl3 as solvent) δ / ppm: 18.62 (C-1), 37.85 (C-2), 35.83 (C-3), 52.83 (C-4), 37.40 (C-5), 38.27 (C-6), 24.00 (C-7), 33.44 (C-8), 134.61 (C-9), 146.98 (C-1) The concentrations were 126.87 (C-11), 145.69 (C-12), 123.86 (C-13), 124.14 (C-14), 37.08 (C-15), 25.24 (C-16), 25.38 (C-17), 24.04 (C-18), 46.73 (C-19), 44.88 (C-20), and 8.33 (C-21). The signal peaks at 134.61, 146.98, 126.87, 145.69, 123.86, and 124.14 ppm belong to the six carbon atoms on the benzene ring, while the signal peaks at 44.88 and 8.33 ppm belong to the two carbon atoms of the ethyl group, indicating the presence of an ethylsulfonamide structure in the compound.

[0083] Figure 3The chemical shifts of all H elements in DBS1 are shown in the figure; the positions of each hydrogen atom are shown in δ / ppm: 7.00 (C14-1H), 6.98 (C11-1H), 6.89 (C13-1H), 4.58 (C20-2H), 3.00 (C15-1H), 2.91 (C8-2H), 2.70 (C19-2H), 1.97 (NH-1H), 1.71-1.40 (12H, C1-2H, C2-2H, C4-1, C6-2H, C7-2H, C17-3H), 1.31-1.03 (12H, C16-6H, C8-3H, C21-3H). The values ​​of 1.71–1.40, 2.91, and 3.00 ppm belong to the rigid framework structure of rosin tricyclic diterpenoids; the values ​​of 6.89–7.00 and 1.31–1.03 ppm belong to hydrogen atoms on the benzene ring; the values ​​of 1.97 and 2.70 ppm are hydrogen atoms on the amino and ethyl groups, respectively, indicating that the synthesized compound contains a rosin structure; the characteristic peak at 4.58 ppm belongs to the ethyl group, indicating that the compound contains an ethylsulfonamide structure.

[0084] In summary, the product DBS1 synthesized in Example 1 is a dehydroafiminosulfonamide derivative.

[0085] Furthermore, the present invention also provides other related dehydroaflavinol sulfonamide derivatives to fully illustrate the effects of the present invention, as follows:

[0086] Example 3

[0087] The only difference from Example 1 is that ethyl sulfonyl chloride is replaced with isopropyl sulfonyl chloride, and the molar ratio of dehydroabimethylamine and alkyl sulfonyl chloride in the reaction is 1:0.5.

[0088] The resulting product is denoted as DBS3, and its structural formula is: The yield was 57.6%.

[0089] Example 4

[0090] The only difference from Example 1 is that ethyl sulfonyl chloride is replaced with n-butyl sulfonyl chloride, and the molar ratio of dehydroabimethylamine and alkyl sulfonyl chloride in the reaction is 1:2.

[0091] The resulting product is denoted as DBS4, and its structural formula is: The yield was 59.4%.

[0092] Example 5

[0093] The only difference from Example 1 is that ethyl sulfonyl chloride is replaced with isobutane sulfonyl chloride, and the molar ratio of dehydroabimethylamine and alkyl sulfonyl chloride in the reaction is 1:1.2.

[0094] The resulting product is designated DBS5, and its structural formula is: The yield was 76.8%.

[0095] In order to more clearly illustrate the excellent performance of the dehydroabietylsulfonamide derivatives of the present invention when used as drilling fluid additives, the products DBS1, DBS2, DBS3, DBS4, DBS5 obtained in the examples, dehydroabietic acid (as a comparison), dehydroabietylamine (as a comparison), and dehydroabietyl glycerol ester (as a comparison) were used as drilling fluid additives, and the performance of the corresponding drilling fluids was evaluated.

[0096] Among them, the preparation process of the drilling fluid is as follows:

[0097] Add 240 mL of synthetic oil to a high-speed stirring cup, and sequentially add 24 g of the main emulsifier HT-MUL, 7.5 g of organophilic clay, 60 mL of 20% CaCl2 aqueous solution, 6 g of CaO, 12 g of filtrate reducer, and 480 g of barite with a density of 1.8 g / cm 3 while stirring at a high-speed stirring speed of 11,000 r / min for 20 min, then add 2% additive and stir for 10 min. After all raw materials are added, stir together for 40 min to obtain the oil-based drilling fluid base fluid.

[0098] The testing process of the obtained drilling fluid is as follows:

[0099] 1. High-temperature aging test

[0100] Fill the above-prepared drilling fluid into a high-temperature stainless steel tank, fill it with nitrogen at 1.0 MPa, place it in a digital roller heating furnace, roll it at different temperatures for 16 h, and then cool it to 25 °C after taking it out.

[0101] 2. Rheological property test

[0102] Before and after aging (at 180 °C for 16 h) of the prepared drilling fluid samples, they were respectively tested at room temperature using a six-speed viscometer. The stable readings of Φ600 were sequentially recorded at different rotation speeds. Apparent viscosity: AV = ηapp = Φ600 / 2 mPa·s;

[0103] Refer to the national standard "GB / T 29170-2012 Petroleum and Natural Gas Industry - Drilling Fluid Laboratory Testing" to test the rheological parameters of the drilling fluid.

[0104] 3. Barite settling test method

[0105] The barite settling test method was established for different settling conditions, such as simulating static conditions, dynamic conditions, tilt angles, flow circuits, high temperature and high pressure, etc. In the present invention, the static settling test method is adopted.

[0106] Static settling test is a method for evaluating the settling tendency of drilling fluid under static conditions in the wellbore. It involves adding drilling fluid to a stainless steel container, allowing it to stand statically at a specific temperature for a period of time, and then measuring the density ρ of the upper part of the drilling fluid column (lower layer of free liquid). top and the density ρ at the bottom bottom The static settlement factor SF is calculated using the following formula:

[0107] SF = ρ bottom / (ρ bottom +ρ top )

[0108] When SF = 0.50, it indicates that no static settlement has occurred; when SF > 0.52, it indicates that the static settlement stability is poor.

[0109] 4. Demulsification voltage (ES) measurement

[0110] Filter large solids from the sample using a 12-well sieve or a Marshall funnel. Place the sample in a heatable beaker or heatable viscosity cup. Adjust and maintain the temperature of the container and sample at 50±2℃ (120±5℉). Thoroughly wipe the electrode probe (demulsification voltage tester) clean with a paper towel, wiping the electrodes several times. Stir the oil base with the probe to ensure it is suitable for use in slurry. If the oil base is unsuitable, other oils or reagents (such as isopropanol) can be used; clean and dry the probe before testing. Press the "Test" button; the voltage will begin to rise automatically. Do not move the probe during the test. The voltage stops increasing when the breakdown voltage is reached; record this voltage value as the dielectric breakdown voltage (electrical stability reading).

[0111] The test results are detailed in Table 1.

[0112] Table 1

[0113]

[0114]

[0115] As shown in Table 1, after adding the product of the embodiment, the rheological parameters of the drilling fluid changed less before and after aging compared to the drilling fluid base slurry, indicating that the product of the embodiment of the present invention has excellent temperature resistance and makes the drilling fluid have low viscosity and viscosity stability; the demulsification voltage is as high as 1300V or more, indicating strong emulsion stability. The sedimentation factor SF is around 0.51, indicating that it has a very good anti-barite sedimentation effect.

[0116] Comparative Examples 1-3 replaced the dehydroabsinosulfonamide derivative with the raw materials dehydroabsinolic acid, the structural analog rosin amine, and rosin ester. The demulsification voltage of rosin ester dropped sharply to below 400V, proving that the emulsion structure of the system was destroyed and the drilling fluid could not be used normally.

[0117] The present invention is described in detail through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the components used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0118] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0119] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0120] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A dehydroaflavinol sulfonamide derivative, characterized in that, The structural formula of the dehydroaflavinol sulfonamide derivative is: In the formula, R is selected from straight-chain or branched alkyl groups with 2-20 carbon atoms.

2. The dehydroaflavinamide derivative as described in claim 1, characterized in that, The R is selected from straight-chain or branched alkyl groups having 2-10 carbon atoms.

3. The dehydroaflavinamide derivative as described in claim 2, characterized in that, The R is selected from one of ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, or n-hexyl.

4. The dehydroaflavinamide derivative as described in claim 1, characterized in that, The dehydroaflavinol sulfonamide derivative is selected from any one of the following compounds:

5. A method for preparing the dehydroaflavinol sulfonamide derivative as described in any one of claims 1-4, characterized in that, The preparation method includes: The dehydroafylamine solution was added dropwise to an alkylsulfonyl chloride solution to carry out the reaction, and the reaction solution was obtained. The reaction solution was extracted, and the resulting organic phase was dried, filtered, and rotary evaporated to obtain a dehydroafiminosulfonamide derivative.

6. The preparation method according to claim 5, characterized in that, The molar ratio of dehydroabimethamine to alkylsulfonyl chloride in the reaction is 1:(0.5-2).

7. The preparation method according to claim 5, characterized in that, The reaction time is 2-6 hours.

8. The preparation method according to claim 5, characterized in that, The reaction temperature is 25-80℃.

9. The preparation method according to claim 6, characterized in that, The molar ratio of dehydroabimethamine to alkylsulfonyl chloride in the reaction is 1:(1-1.2).

10. The preparation method according to claim 7, characterized in that, The reaction time is 3-4 hours.

11. The preparation method according to claim 8, characterized in that, The reaction temperature is 30-60℃.

12. The preparation method according to claim 5, characterized in that, A weak organic base was also added dropwise during the reaction.

13. The preparation method according to claim 12, characterized in that, The organic weak base is selected from pyridine and / or triethylamine.

14. A drilling fluid, characterized in that, The drilling fluid includes the dehydroafamidosulfonamide derivative as described in any one of claims 1-4.

15. The drilling fluid as described in claim 14, characterized in that, The drilling fluid includes oil-based drilling fluid.

16. The drilling fluid as described in claim 15, characterized in that, The drilling fluid comprises: an oil phase, an emulsifier, an organic clay, calcium, a filtration loss reducer, a weighting agent, and the dehydroafamidine sulfonamide derivative.

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